Bonneville Bradford Island Branch B Fish Ladder Repair

This emergency project for the historic Bonneville Branch B Fish Ladder on Bradford Island at the Bonneville Dam on the Columbia River was necessary to repair a scoured fish ladder structure and replace the failed riprap revetment. This work involved a very strict in-water work window to complete the fish ladder and allow the US Army Corps of Engineers (USACE)use of the ladder for migrating salmon.

The undermined fish ladder floor slab was repaired by pouring approximately 250 cubic yards of structural concrete underwater to form a suitable foundation for the fish ladder. The grouted riprap revetment work involved placement of 450 tons of rock delivered to the project site via barge and tugboat on the Columbia River.